Field of the Invention
The present invention relates to a thermosensitive and photocrosslinkable composite material that may be used in three-dimensional scaffold printing.
Description of the Related Art
In the US alone, around eight million surgical procedures are performed every year to treat maladies related to damaged tissue; over 70,000 patients are waiting for organ transplants, and more than 100,000 people die each year with tissue related disorders. The current demands for replacement organs and tissues far exceed the supply, and research indicates that this gap will continue to widen. The history of reconstructive surgery began with ablative surgery, followed by tissue and organ transplantation, leading to contemporary tissue reconstruction. In recent years, the main focus of tissue engineering has been on the culture of cells. In general, tissues are three-dimensional (“3-D”) structures composed of living cells and a support structure. Therefore, the generation of functional implants from living cells relies heavily on the fabrication of the 3-D structure. Tissue engineering has been successfully used to replace skin, blood vessels, and cardiac tissue. For a new generation of complex 3-D implants, more sophisticated technology is required. Complex shapes and structures can be created from special biodegradable and biocompatible polymers so that a tissue's natural support structure replaces the synthetic scaffold as it degrades. The materials should therefore be considered only as a temporary support for cell growth and cell adhesion. For engineering soft tissues, ideal scaffolds are made of synthetic or natural biopolymers providing porous (up to 90%) support structure, thus mimicking the natural extracellular matrix environment in which cells attach, multiply, migrate and function. The pores in the scaffold must be interconnected to allow efficient nutrient transfer and waste exchange to permit survival of any cells cultured on the scaffold. The pores should typically be 100-300 μm, around 5-10 times a cell's diameter. Porous scaffolds facilitate tissue formation while providing adequate mechanical strength to withstand implantation and permit normal physiological function in the human body.
There exists a need for a temporary scaffolding material that is thermoresponsive and photocrosslinkable as well as designed and fabricated to be used in many different applications of solid freeform fabrication.